Results 81 to 90 of about 2,512 (186)

Multiple Outbursts of Halley-type Comet 12P/Pons–Brooks

The Astronomical Journal
We present optical observations of the Halley-type comet 12P/Pons–Brooks (12P) on its approach to perihelion. The comet was active even in the first observations at ∼8 au.
David Jewitt, Jane Luu
doaj   +1 more source

Nucleus and Postperihelion Activity of Interstellar Object 3I/ATLAS Observed by the Hubble Space Telescope

The Astrophysical Journal Letters
We report the detection of the nucleus of interstellar object 3I/ATLAS, using a nucleus extraction technique on Hubble Space Telescope (HST) observations taken between 2025 December and 2026 January.
Man-To Hui, David Jewitt, Max J. Mutchler, Jessica Agarwal, Yoonyoung Kim   +4 more
doaj   +1 more source

Activity Analysis on 68P/Klemola and 78P/Gehrels 2 in 2018–2020 Perihelion Passage

The Astronomical Journal
We performed secular monitoring broadband photometric observations on Jupiter Family Comets (JFCs) 68P/Klemola and 78P/Gehrels 2 from 2018 November to 2020 March with the Yaoan High Precision Telescope.
Ruiqi Xu, Jianchun Shi, Yuehua Ma, Yingqi Xin, Fan Li, Ye Yuan   +5 more
doaj   +1 more source

Watching a Comet Turn On: High Spectral Resolving Power Observations of Comet C/2017 K2 (PanSTARRS)

The Planetary Science Journal
We report high spectral resolving power optical observations of comet C/2017 K2 (PanSTARRS) as it approached the Sun. This comet was discovered when it was 16 au from the Sun. At discovery, the comet had a large and relatively bright coma.
Anita L. Cochran, Adam J. McKay, Youssef Moulane   +2 more
doaj   +1 more source

Covertly Active Comet (139359) 2001 ME1

The Planetary Science Journal
On 2018 November 18, coronagraphs onboard the Solar and Heliospheric Observatory (SOHO) captured an unrecognized comet crossing its fields of view. We identified this comet to be the minor planet (139359) 2001 ME _1 , whose previously unnoticed dust ...
Qicheng Zhang, Quanzhi Ye, Karl Battams, Matthew M. Knight, Worachate Boonplod, Rainer Kracht   +5 more
doaj   +1 more source

Spectral Characteristics of Interstellar Object 3I/ATLAS from SOAR Observations

The Astrophysical Journal Letters
Interstellar objects (ISOs) provide unique insights into the building blocks and conditions of extrasolar planetary systems. The newly discovered object, 3I/ATLAS (C/2025 N1), represents the third known ISO after 1I/’Oumuamua and 2I/Borisov.
Thomas H. Puzia, Rohan Rahatgaonkar, Juan Pablo Carvajal, Prasanta K. Nayak, Baltasar Luco   +4 more
doaj   +1 more source

Very Large Telescope Observations of Interstellar Comet 3I/ATLAS. II. From Quiescence to Glow: Dramatic Rise of Ni i Emission and Incipient CN Outgassing at Large Heliocentric Distances

The Astrophysical Journal Letters
We report Very Large Telescope spectroscopy of the interstellar comet 3I/Asteroid Terrestrial-impact Last Alert System (C/2025 N1), from r _h  ≃ 4.4 to 2.85 au, using X-Shooter (300–550 nm, R  ≃ 3000) and the Ultraviolet and Visual Echelle Spectrograph ...
Rohan Rahatgaonkar, Juan Pablo Carvajal, Thomas H. Puzia, Baltasar Luco, Emmanuel Jehin, Damien Hutsemékers, Cyrielle Opitom, Jean Manfroid, K. Aravind, Michaël Marsset, Bin Yang, Laura Buchanan, Wesley C. Fraser, John Forbes, Michele Bannister, Dennis Bodewits, Bryce T. Bolin, Matthew Belyakov, Matthew M. Knight, Colin Snodgrass, Erica Bufanda, Rosemary Dorsey, Léa Ferellec, Fiorangela La Forgia, Manuela Lippi, Brian Murphy, Prasanta K. Nayak, Mathieu Vander Donckt   +27 more
doaj   +1 more source

Dust Production Rates in Jupiter-family Comets. II. Trends and Population Insights from ATLAS Photometry of 116 JFCs

The Planetary Science Journal
Jupiter-family comets (JFCs) have orbital periods of less than 20 yr and therefore undergo more frequent sublimation compared to other comet populations.
A. Fraser Gillan, Alan Fitzsimmons, Larry Denneau, Robert J. Siverd, Ken W. Smith, John L. Tonry, David R. Young   +6 more
doaj   +1 more source

COSINE (Cometary Object Study Investigating Their Nature and Evolution). I. Project Overview and General Characteristics of Detected Comets

The Astrophysical Journal Supplement Series
We present the first results from the Cometary Object Study Investigating their Nature and Evolution (COSINE) project, based on a uniformly processed data set of 484 comets observed over the full 15 yr duration of the Wide-field Infrared Survey Explorer (
Yuna G. Kwon, Dar W. Dahlen, Joseph R. Masiero, James M. Bauer, Yanga R. Fernández, Adeline Gicquel, Yoonyoung Kim, Jana Pittichová, Frank Masci, Roc M. Cutri, Amy K. Mainzer   +10 more
doaj   +1 more source

Spectroscopic identification of water emission from a main-belt comet. [PDF]

Nature, 2023
Kelley MSP, Hsieh HH, Bodewits D, Saki M, Villanueva GL, Milam SN, Hammel HB.   +6 more
europepmc   +1 more source